Altitude Estimation Using Calibrated Reference Pressure Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the altitude of a mobile device using barometric pressure are inaccurate due to unreliable reference pressures from sources like crowdsourced weather stations, which lack the precision required for navigation and location services.
Innovation Solution
A system and method for determining the accuracy of reference pressures and adjusting them using gold-standard sensors and reference sensors, which involve identifying available reference pressures, monitoring temporal and pressure measurement conditions, and applying calibration values to ensure accurate altitude calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If crowdsourced weather station data is used as reference pressure, then data availability increases, but measurement precision deteriorates
Solution Approach 1:
The patent introduces a server as an intermediary that receives reference pressure data from multiple crowdsourced weather stations, evaluates their accuracy using quality control metrics, and selects or combines them to produce a reliable reference pressure. This intermediary process resolves the contradiction by filtering out low-quality data while maintaining access to multiple data sources.
Solution Approach 2:
The system changes the parameter of reference pressure by dynamically selecting or combining data from different weather stations based on their quality metrics, temporal proximity, and spatial relevance. This parameter transformation converts unreliable individual measurements into a reliable composite reference pressure.
2Reliability
If multiple reference pressure sensors are combined, then reliability improves, but device complexity increases
Solution Approach 1:
The patent merges data from multiple reference pressure sensors through a server that combines their readings using quality-weighted algorithms. This merging process improves reliability by averaging out individual sensor errors while the centralized server architecture manages the complexity, preventing it from propagating to the mobile device level.
3Measurement precision
If remote sensor accuracy is improved, then altitude estimation accuracy improves, but loss of information increases due to stricter quality control requirements
Solution Approach 1:
The system performs preliminary quality control evaluation and calibration of reference pressure data before using it for altitude estimation. By pre-processing the data to identify and correct quality issues, the system ensures that only reliable data proceeds to the altitude calculation, minimizing information loss while maximizing accuracy.
Solution Approach 2:
The patent implements feedback mechanisms where the system continuously monitors the quality of reference pressure data and adjusts its selection and combination strategies accordingly. This feedback loop ensures that the strictest quality control is applied only when necessary, balancing accuracy requirements with data availability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of altitude determination to within one to two meters, suitable for navigation and emergency services, by improving the quality control of weather data and ensuring high pressure and temporal resolution.
Implementation Method 1
A barometric-based approach for estimating an altitude of a mobile device requires (i) an accurate estimate of pressure at a location of the mobile device
Implementation Method 2
The altitude of the mobile device, hmobile is computed using Equation 1, where href is substituted for hsensor and Pref is substituted for Psensor
Data Source
AI summary
Identifying and estimating values of atmospheric conditions for use in estimating an altitude of a mobile device. Systems and methods for monitoring one or more conditions before estimating an altitude of a mobile device may receive a reference pressure that was computed using a measurement of pressure from a first reference pressure sensor at a first location, wherein the received reference pressure specifies an estimated pressure for a reference altitude, and determine if a threshold change in measured pressure by the first reference pressure sensor is detected. If the threshold change in measured pressure is detected, the systems and methods may compute a calibration value for the first reference pressure sensor, or if the threshold change in measured pressure is not detected, the systems and methods may identify a previously-determined calibration value. The systems and methods may then compute an adjusted reference pressure using the received reference pressure and either the computed calibration value or the previously-determined calibration value, and compute an estimate of the altitude of the mobile device using the adjusted reference pressure and a measurement of pressure from the mobile device.